Eyesight is one of the most important ways we interact with the world, playing a significant role in learning, social interaction, and daily activities.
As the American population ages, adapting to low vision or blindness will become increasingly necessary.
The National Eye Institute predicts that “between 2010 and 2050, the estimated number of people affected by the most common eye diseases will double.”
That means a lot of impact on our social interactions and daily lives.
Globally, there is good news in that an estimated 80% of vision loss is preventable.
Around the world, rates of infectious disease affecting the eyes have fallen significantly in the last quarter-century.
Research is making headway into treatments based on technologies that were nearly impossible to conceive of just two decades ago, including gene therapies using CRISPR to treat retinal disease.
While cutting-edge treatments like these give ophthalmologists new tools to treat eye disease, some eye surgery is at least as old as ancient Greece, Egypt, and Persia. That long history means that eye care professionals have time-tested evidence on what approaches work in what situations. Many eye diseases are not curable at this time, but treatment can improve the quality of life for patients and slow the progression of the damage.
Here are three examples of eye diseases that are not curable but nevertheless treatable. Patients with these conditions can live full and independent lives. Early detection, a healthy lifestyle, and regular consultation with an ophthalmologist all help patients maximize their vision.
1. Age-Related Macular Degeneration
There are several types of macular degeneration. The most common is age-related (AMD). More than 10 million Americans suffer from macular degeneration, and most of those are over age 60. The most common of AMD is by far the dry type. The dry type can progress into the much more serious wet type if left untreated.
AMD affects the center of a person’s field of vision. Blurriness in the central field, with clear peripheral vision, is the hallmark of macular degeneration. Edges remain in focus, but objects that you try to focus on may be blurry, unusually bright or dark, appear distorted or even become lost in a blank spot.
This happens because weakened blood vessels at the back of the eye leak fluid that distorts vision. Over time, the leakage damages sensitive photoreceptors on the retina.
While it is impossible to reverse the damage, treatment can slow the progression of vision loss. There are more treatment options during the earlier, dry stage of the disease. During the wet phase, leaking blood vessels can be sealed with a laser.
Recently, additional techniques have been developed for sealing the vessels more precisely. However, “even the most successful treatments do not preclude reoccurrence, making multiple treatments likely,” according to the American Macular Degeneration Foundation. Future areas of promising include gene editing, and new drugs are in clinical trials across the world, already helping some patients.
In contrast to high-tech procedures, lifestyle changes are a first-line defense. While some risk factors include age, race, family history, and genes, other risk factors include behaviors that can be changed. The National Eye Institute notes that “researchers have found links between AMD and some lifestyle choices, such as smoking.” They recommend the following healthy choices to help slow the disease’s progression:
- Avoid smoking.
- Exercise regularly.
- Maintain normal blood pressure and cholesterol levels.
- Eat a healthy diet rich in green, leafy vegetables, and fish.
2. Stargardt Disease
Stargardt disease is caused by a build-up of toxic byproducts in the eye. Vitamin A is synthesized within the body from nutrient beta carotene, which is a building block available in deep orange foods and other vegetables. In most people, the processing of one nutrient into another includes a phase that clears out the “garbage” into the body’s waste removal system, but in patients with Stargardt, a mutation in the ABCA4 gene inhibits this ability to remove toxic byproducts, such as lipofuscin.
Dramatic advances in genomic technology have given researchers insight into the causes of many retinal diseases, including Stargardt. Some parts of treatment are similar to that for AMD since Stargardt is a type of macular degeneration. NIH describes current research into synthetic alternatives to vitamin A that might “reduce the build-up of lipofuscin and other toxic byproducts in the retina.” It is important to avoid multivitamins or other supplements with a higher amount of vitamin A than the FDA’s recommended daily allowance.
The other important lifestyle recommendation is to avoid smoking.
Because there is no cure, patients learn to adapt to changes in their vision. Total blindness is very rarely in Stargardt, but patients typically begin to need low-vision aids by late adolescence to their mid-20s. Being in bright sunlight is involved in triggering the body to transform beta carotene into vitamin A, so covering up with dark sunglasses and hats is recommended to slow this cycle down.
3. Retinitis Pigmentosa
Another inherited disease is retinitis pigmentosa (RP). This one, however, is the product of not one but several genes that together impair the retina’s ability to process incoming light. Like Stargardt, patients usually do not go completely blind.
RP is actually a group of similar inherited eye conditions affecting the rod and cone cells at the back of the eye in the retinal tissue. In some patients, ability to see color is affected. Most experience tunnel vision and night blindness. Occasionally, patients with RP may have other health issues because the same genes that cause RP can be involved in other body systems as well.
Also like Stargardt, there is no cure at this time. Very recently, however, “the first gene therapy for inherited retinal disease takes a step closer to European approval.” With scientific advances in genetics, new treatments may be possible in the future.
It is recommended that patients incorporate counseling into their treatment plan to address the emotional impacts of losing significant vision at an early age. Genetic counseling can also help potential parents with RP make an informed decision. Simple tests can determine if the patient’s partner is a carrier of the genes involved in RP.